The SAS motto: Staff Sergeant Mark McKay, 35, is accused of stealing more than £100,000

A former SAS sergeant claimed he made profits of more than £200,000 in just 12 weeks by selling alcohol to thousands of Coalition colleagues serving in Iraq.

Staff Sergeant Mark McKay, 35, told a court he set up a personal "retail facility" when he was attached to 22 Special Air Service (SAS) for the elite unit's deployment for the Gulf War between February and May 2003.

He was arrested by military police in April 2004 after £100,175 allegedly stolen from an SAS cash office, was found hidden in plant pots outside his home in Ballykelly, Northern Ireland, where he was posted after leaving the SAS.

McKay, on trial at Bulford Military Court in Wiltshire, denies stealing Ministry of Defence funds.

John Mackenzie, defending, told the court martial that McKay earned the cash legitimately by running a private venture, funded with his own money, for SAS troops and large numbers of soldiers from other Coalition countries based at the same compound, in "a country bordering Iraq".

McKay ran this service in addition to his official duties as a finance sergeant, which involved accounting for and providing money for SAS operational requirements, a job he did "meticulously", according to his then boss, Major Gerald Crowe, of AGC.

As part of his job in 2003, McKay was one of the only soldiers permitted to go off the base to the nearby city to buy supplies and draw funds to pay contractors employed in the setting up of the camp.

McKay realised there was a market among the SAS troops at the base for alcohol and cigarettes, the court heard.

"It also became clear that there was a need for other forces (numbering thousands) in this camp for the same sort of arrangement," Mr Mackenzie said.

The astonishing profits McKay made from his alcohol shop were achieved by buying cases of beer for £10 and selling them on to Coalition troops for £37 or £50, Mr Mackenzie told the court.

In the first week he made £1,502 from his enterprise, which, said Mr Mackenzie, was carried out with the permission of the unit quarter master.

In week six of the deployment, he made £16,228 in profit, the trial heard.

"His estimate is that over the 12 weeks this venture made a 371,000 US dollars (£185,825) profit," said Mr Mackenzie.

The barrister, cross-examining Maj Crowe, asked: "If Sgt McKay seeded this venture with his own money then it's his money, isn't it?"

Maj Crowe, who described Sgt McKay as "very, very good at his job", said he was unaware of his Gulf-based alcohol shop.

He said: "He should not have been running his own business. It is not appropriate. I'm shocked to hear that. I would be very surprised if we were allowed to sell alcohol to (other countries') forces."

Mr Mackenzie said Sgt McKay was given permission "to do exactly that, so effectively there was a retail facility for the (SAS) squadron, and with the approval of the quarter master, he did the same thing for the whole of the camp.

"This was his own venture and I think we can use this expression: the whole thing 'ran away with him', because of the number of people (several thousand) and their needs."

The prosecution allege that McKay stole the money from an SAS cash office at the regiment's Hereford base.

The trial has heard how McKay put £100,175 of his "profits" in a safe before transferring it to a terracotta plant pot outside his front door in Ballykelly.